CN107162027B - A kind of preparation method of anhydrous magnesium chloride with high purity - Google Patents
A kind of preparation method of anhydrous magnesium chloride with high purity Download PDFInfo
- Publication number
- CN107162027B CN107162027B CN201710601232.6A CN201710601232A CN107162027B CN 107162027 B CN107162027 B CN 107162027B CN 201710601232 A CN201710601232 A CN 201710601232A CN 107162027 B CN107162027 B CN 107162027B
- Authority
- CN
- China
- Prior art keywords
- mgcl
- mixture
- anhydrous
- homogeneous mixture
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/26—Magnesium halides
- C01F5/30—Chlorides
- C01F5/34—Dehydrating magnesium chloride containing water of crystallisation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
- C01P2006/82—Compositional purity water content
Abstract
The invention discloses a kind of preparation methods of anhydrous magnesium chloride with high purity, include the following steps: the first step, with solid MgCl2·6H2O and solid NH4Cl prepares ammonium carnallite NH in the at a temperature of generation solid state reaction not higher than 100 DEG C4MgCl3·6H2O and NH4The homogeneous mixture of Cl；Second step, by ammonium carnallite NH4MgCl3·6H2O and NH4The mixture of Cl is dehydrated at 200~350 DEG C, obtains anhydrous NH4MgCl3And NH4The homogeneous mixture of Cl；Third step, by NH4MgCl3And NH4The homogeneous mixture of Cl thermally decomposes under vacuum conditions and NH is distilled off4Cl obtains anhydrous MgCl2.The preparation method process is easy to operate, and solvent usage amount has been reduced to minimum, therefore low energy consumption, environmentally friendly.
Description
Technical field
The present invention relates to the preparation methods of a kind of ammonium carnallite and anhydrous magnesium chloride, more particularly to one kind to be based on rare earth
The ammonium carnallite preparation method of chemical reaction, and the method for vacuum distillation ammonium carnallite manufacture anhydrous magnesium chloride, belong to electrolysis
Manufacture the nonferrous metallurgy technical field of magnesium metal.
Background technique
The anhydrous magnesium chloride MgCl of high-purity2It is the raw material of electrolysis production magnesium metal, more attracting conventionally manufactured side
Method includes that (1) makes MgCl under HCl atmosphere2·6H2O dehydration.Such method carries out at high temperature, the water of HCl present in system
Vapour is to the seriously corroded of equipment, but it is still industrialized method；(2)MgCl2·6NH3Deamination.MgCl is enabled first2·
6H2O is in liquefied ammonia, organic solvent or in NH4In the aqueous solution of Cl with NH3Reaction generates MgCl2·6NH3, then heat deamination.
Corrosion this method avoid the HCl moisture of first method to equipment, but used ammonia largely less friendly to environment；
(3) ammonium carnallite method.MgCl is enabled first2·6H2O and NH4Cl reacts to obtain ammonium carnallite NH4MgCl3·6H2O, then first low
The lower dehydration of temperature generates low water NH4MgCl3·xH2O (x≤2) then increases temperature again and is allowed to remove NH4Cl obtains MgCl2.Relatively
For, the third method avoids highly corrosive HCl moisture, also avoids being most potential anhydrous chlorine using a large amount of ammonia
Change one of magnesium preparation process.
It has existed the preparation method of ammonium carnallite and prepares MgCl with it2Scheme, but there is no using the method
Carry out industrial report.For example, " a kind of to prepare anhydrous magnesium chloride using Magnesium dichloride hexahydrate disclosed in CN102491384B
Method " Magnesium dichloride hexahydrate and ammonium chloride mixing and ball milling are obtained into ammonium carnallite or containing the mixture of ammonium carnallite first；So
The mixture is heated afterwards and carries out preliminary hydro-extraction, to prepare low water ammonium carnallite or the mixture containing low water ammonium carnallite；Finally
Covering is placed above the product that step (2) obtains, heating is reacted, to prepare anhydrous magnesium chloride.It is said that the invention can
Shorten the production procedure of anhydrous magnesium chloride, improve production efficiency, reduce production cost, and reduces Environmental Inputs cost.Analysis
Process as above, it has been found that the process needs (1) to react in the ball mill；(2) it needs to cover aluminium oxide in low water ammonium carnallite
Or quartz sand.Ball-milling reaction has that noise is big, energy consumption is high；The aluminium oxide or quartz sand of covering can pollution products.
Low heating temperature solid state reaction is one kind that new spring professor Nanjing University Xin study group finds and furthers investigate
It can be in solid state reaction (Lei Lixu, Xin Xinquan, " solid-state chemical reaction and the solid knot that room temperature and its neighbouring temperature occur
Structure ", chemistry notification, 1997, (2) 1).The reactant of such reaction is usually that molecular solid and/or hydrated metal salt (have weak
The ionic compound of ionic bond), they are all solid at normal temperature, can be under low heating temperature (referring to room temperature~100 DEG C) not
It needs to carry out under the conditions of solvent is existing, therefore has energy-saving and environment-friendly characteristic (because eliminating energy consumption, time-consuming, high pollution wind
The solvent treatment process of danger).MgCl2·6H2O and NH4The reaction of Cl conforms exactly to the requirement of rare earth chemical reaction, they
The water of reaction process generation can be partially dissolved in and help to spread, this promotes us to carry out solid MgCl2·6H2O and solid
Body NH4Reaction of the Cl under low heating temperature.
Our research finds immediately, solid MgCl2·6H2O and solid NH4The mixture of Cl is not required at room temperature
Grinding, which can directly react, generates NH4MgCl3·6H2O (that is the ball milling of CN102491384B is unnecessary), but
It is to react relatively slowly.We make solid MgCl thus2·6H2O and solid NH4Cl is by 1:1~1:3 molar ratio in room temperature condition
Under be uniformly mixed, and add a small amount of water (no more than the 10% of solid gross mass) for promoting reaction process, then
Closed reactor is placed in 100 DEG C of insulating boxs below, and by being no more than reaction in 12 hours, NH can be obtained4MgCl3·
6H2O and NH4The mixture of Cl.First (< 350 DEG C) dehydrations at low temperature by the mixture, then at relatively high temperatures (< 700 DEG C)
NH is sloughed in vacuum distillation4Cl obtains the MgCl of high-purity2.Process is easy to operate, does not use solvent substantially, therefore low energy consumption, right
It is environmental-friendly.
Summary of the invention
Technical problem: the first object of the present invention is to provide a kind of environment amenable ammonium for reducing solvent processing as far as possible
The solid state reaction technology of preparing of carnallite；The second object of the present invention is to provide a kind of thermally decomposed by ammonium carnallite vacuum and makes
The method of standby anhydrous magnesium chloride with high purity, it is therefore an objective to it is inadequate to eliminate ammonia nitrogen recovery rate deficiency and decomposition rate in prior art
Fast problem.
Technical solution: a kind of preparation method of anhydrous magnesium chloride with high purity of the invention includes the following steps:
The first step, with solid MgCl2·6H2O and solid NH4Cl occurs solid state reaction and prepares ammonium carnallite
NH4MgCl3·6H2O and NH4The homogeneous mixture of Cl；
Second step, by ammonium carnallite NH4MgCl3·6H2O and NH4The mixture vacuum distillation dehydration of Cl, obtains anhydrous
NH4MgCl3And NH4The homogeneous mixture of Cl；
Third step, by NH4MgCl3And NH4The homogeneous mixture of Cl thermally decomposes under vacuum conditions and NH is distilled off4Cl,
Obtain anhydrous MgCl2。
Wherein:
In the first step, solid state reaction prepares ammonium carnallite NH4MgCl3·6H2O includes 2 steps: firstly,
Take MgCl2·6H2O and NH4Cl is added the water for being not higher than their gross masses 10%, is uniformly mixed；Secondly, equal by what is obtained
Even mixture moves into a closed reactor, then arrives in 50~100 DEG C of at a temperature of heat preservation less than 12 hours
NH4MgCl3·6H2O and NH4The homogeneous mixture of Cl.
The MgCl2·6H2O and NH4Cl molar ratio is weighed according to 1:1~1:3.
In second step, ammonium carnallite NH4MgCl3·6H2O and NH4The mixture of Cl is evaporated under reduced pressure to obtain NH4MgCl3With
NH4The homogeneous mixture of Cl is that the air suction of dry cleansing is being maintained between 200~350 DEG C under condition of negative pressure
NH4MgCl3·6H2O and NH4In the homogeneous mixture of Cl, the water vapour for generating pyrolysis is all taken away, to obtain anhydrous
NH4MgCl3And NH4The mixture of Cl
In third step, anhydrous NH4MgCl3And NH4The mixture of Cl moves into a tool, and there are two the vacuum distilling apparatuses of warm area
In, high-temperature region is controlled between 400~700 DEG C, and low-temperature space is at 150 DEG C hereinafter, making NH4MgCl3In high-temperature region, thermal decomposition is generated
NH3With HCl steam in low-temperature space chemical combination, NH is formed again4Cl crystal, to make NH4Cl is all recycled.
It is chemically seen in principle, the synthetic reaction of ammonium carnallite is as follows:
MgCl2·6H2O+NH4Cl=NH4MgCl3·6H2O (1)
It is the combination reaction of a standard.Studies have shown that MgCl2·6H2O and NH4Cl can be not added any at room temperature
It is directly reacted in the case where other reagents, generates ammonium carnallite NH4MgCl3·6H2O, but speed is fairly slow.In addition suitable quantity of water
In the case where, most MgCl2·6H2O and NH4Cl is in solid state, but also respectively has a small amount of water for being dissolved in addition on a small quantity
In.It is dissolved in the part MgCl of water2·6H2O and NH4Cl be very easy to migration, therefore they can in system somewhere chemical combination shape
At NH4MgCl3·6H2O, and crystallize out.Therefore, this small amount of water makes all MgCl just as catalyst2·6H2O and
NH4Cl reaction is converted into NH4MgCl3·6H2O.The water of addition may also help in excessive NH4Cl is evenly distributed on NH4MgCl3·
6H2The surface of O, to be beneficial to subsequent reaction.
Ammonium carnallite dehydration is easier than hydrated magnesium chloride, because of NH therein4 +With more Cl-Presence weaken
Mg2+And H2Co-ordinate covalent bond between O.The NH being present in excess4Cl (known Mg (OH) itself2It is dissolved in NH4The aqueous solution shape of Cl
At MgCl2With the aqueous solution of ammonia) and its just there is at 100 DEG C or more decomposition generate NH3With the tendency of HCl, Mg can be inhibited jointly
(H2O)x 2+Hydrolysis generates Mg (OH) (H2O)x +Process (the latter can with HCl react be then converted to MgCl2).Therefore, ammonium light halogen
Stone dehydration can generate NH under conditions of being lower than 350 DEG C4MgCl3:
NH4MgCl3·6H2O=NH4MgCl3+6H2O (2)
The NH of generation4MgCl3The chance (because there is no water) not hydrolyzed at all in high vacuum conditions, will not send out
Raw oxidation reaction (3) (because oxygen is not present), can only decompose and generate anhydrous MgCl2(4):
MgCl2+1/2O2=MgO+Cl2 (3)
NH4MgCl3=MgCl2+NH4Cl (4)
The utility model has the advantages that compared with prior art, remarkable advantage of the invention are as follows: the present invention is prepared using solid state reaction
Ammonium carnallite.By adding a small amount of aqueous solvent, not only accelerate the speed of solid state reaction, evaporation when also making drying and dehydrating
Quantity of solvent reached minimum value, so that energy consumption be made to have obtained reducing significantly.Secondly, having been recycled entirely using vacuum distillation technique
The NH in portion4Cl, and the oxidation of oxygen in air is eliminated, make the net effect MgCl of entire reaction process2·6H2O is de-
Whole water are gone to form anhydrous magnesium chloride.Process does not generate more influences to environment in addition to consuming energy, and energy consumption also obtains
To being effectively reduced.
Detailed description of the invention
Fig. 1 is process flow diagram.
Specific embodiment
It is of the present invention to prepare ammonium carnallite with low fever solid phase reaction and anhydrous chlorine is prepared by ammonium carnallite vacuum decomposition
Change the method for magnesium, including 3 steps:
(1) make solid MgCl2·6H2O and solid NH4Cl occurs solid state reaction and prepares ammonium carnallite NH4MgCl3·
6H2O and NH4The homogeneous mixture of Cl；
(2) make NH4MgCl3·6H2O and NH4The mixture of Cl obtains NH in low temperature dewatering4MgCl3And NH4Cl's is uniform
Mixture；
(3) make NH4MgCl3And NH4The homogeneous mixture of Cl thermally decomposes under vacuum conditions and NH is distilled off4Cl is obtained
Anhydrous MgCl2。
The solid state reaction prepares ammonium carnallite NH4MgCl3·6H2O method are as follows: according to 1:1~1:3 molar ratio
Weigh MgCl2·6H2O and NH4Cl is added the water for being not higher than their gross masses 10%, is uniformly mixed；Secondly, will obtain
Homogeneous mixture moves into a closed reactor (directly the mixed process of the first step directly can also be carried out in this reactor),
Then it is no more than 12 hours in 50~100 DEG C of at a temperature of heat preservation to get NH is arrived4MgCl3·6H2O and NH4The uniform mixing of Cl
Object.
The ammonium carnallite obtains NH in low temperature dewatering4MgCl3Method, be to take out dry air under condition of negative pressure
Enter the NH being maintained between 200~350 DEG C4MgCl3·6H2O and NH4In the homogeneous mixture bed of Cl, generate its pyrolysis
Water vapour all quickly takes away, to obtain anhydrous NH4MgCl3And NH4The mixture of Cl.It is described to be divided by ammonium carnallite Vacuum Heat
Solution obtains anhydrous MgCl2Method, be NH4MgCl3A tool is moved into there are two in the vacuum distilling apparatus of control warm area, control is high
Warm area is between 400~700 DEG C, and low-temperature space is in low-temperature space at 150 DEG C hereinafter, making NH4MgCl3And NH4Cl is thermally decomposed in high-temperature region
The NH of generation3With HCl steam in low-temperature space chemical combination, NH is formed again4Cl crystal, to make NH4Cl is all recycled.
1 MgCl of embodiment2·6H2O and NH4Cl molar ratio is the reaction of 1:1
(1) according to 1:1 molar ratio weighing MgCl2·6H2O and NH4Cl is added in a sealable reactor, and it is total that it is added
The water of quality 10% is sufficiently stirred and is allowed to closed reactor after mixing.It is small that reactor is placed in heat preservation 10 in 90 DEG C of heating baths
When.
(2) product is removed from reactor, is placed in a crucible, then crucible is placed in tube furnace.With 10 degree mins
Speed increases furnace temperature to 200 DEG C, and then heat preservation is until there is no water to distillate.Period vacuumizes, the other end in one end of tube furnace
It connects dry depleted air (can be substituted with nitrogen), maintenance intraductal atmospheric pressure to 0.5atm or so.
(3) one end of closed tube furnace as above and heat preservation, are put into the other end in room temperature environment.Vacuum pump is started, pipe is made
Interior air pressure drops under 0.1atm.Furnace temperature is increased to 500 DEG C with the speed of 10 degree mins, is then kept the temperature until all anhydrous ammonias
Carnallite all resolves into anhydrous magnesium chloride.
2 MgCl of embodiment2·6H2O and NH4Cl molar ratio is the reaction of 1:2
(1) according to 1:2 molar ratio weighing MgCl2·6H2O and NH4Cl is added in a sealable reactor, and it is total that it is added
The water of quality 8%, closed reactor after being then thoroughly mixed them uniformly.Reactor is placed in 80 DEG C of heating baths and keeps the temperature
12 hours.
(2) product is removed from reactor, is placed in a crucible, then crucible is placed in tube furnace.With 10 degree mins
Speed increases furnace temperature to 300 DEG C, and then heat preservation is until there is no water to distillate.Period vacuumizes, the other end in one end of tube furnace
Connect nitrogen, maintenance intraductal atmospheric pressure to 0.5atm or so.
(3) one end of closed tube furnace as above and heat preservation, are put into the other end in room temperature environment.Vacuum pump is started, pipe is made
Interior air pressure drops under 0.1atm.Furnace temperature is increased to 600 DEG C with the speed of 10 degree mins, is then kept the temperature until all anhydrous ammonias
Carnallite all resolves into anhydrous magnesium chloride.
3 MgCl of embodiment2·6H2O and NH4Cl molar ratio is the reaction of 1:3
(1) according to 1:3 molar ratio weighing MgCl2·6H2O and NH4Cl is added in a sealable reactor, and it is total that it is added
The water of quality 5%, closed reactor after being then thoroughly mixed them uniformly.Reactor is placed in 60 DEG C of heating baths and keeps the temperature
8 hours.
(2) product is removed from reactor, is placed in a crucible, then crucible is placed in tube furnace.With 10 degree mins
Speed increases furnace temperature to 250 DEG C, and then heat preservation is until there is no water to distillate.Period vacuumizes, the other end in one end of tube furnace
Connect dry air, maintenance intraductal atmospheric pressure to 0.5atm or so.
(3) one end of closed tube furnace as above and heat preservation, are put into the other end in room temperature environment.Vacuum pump is started, pipe is made
Interior air pressure drops under 0.1atm.Furnace temperature is increased to 700 DEG C with the speed of 10 degree mins, is then kept the temperature until all anhydrous ammonias
Carnallite all resolves into anhydrous magnesium chloride.
Claims (2)
1. a kind of preparation method of anhydrous magnesium chloride with high purity, it is characterised in that this method includes following 3 steps:
The first step, the MgCl for being 1:1~1:3 by molar ratio2·6H2O and NH4A stirred reactor is added in Cl, adds and is not higher than
The water of their gross masses 10%, it is after being uniformly mixed that reactor is closed, then it is less than in 50~100 DEG C of at a temperature of heat preservation
12 hours to get arrive NH4MgCl3·6H2O and NH4The homogeneous mixture of Cl；
Second step, by ammonium carnallite NH4MgCl3·6H2O and NH4The mixture vacuum distillation dehydration of Cl, obtains anhydrous
NH4MgCl3And NH4The homogeneous mixture of Cl；The ammonium carnallite NH4MgCl3·6H2O and NH4The mixture of Cl is evaporated under reduced pressure to
To NH4MgCl3And NH4The homogeneous mixture of Cl is that the air suction of dry cleansing is maintained at 200~350 under condition of negative pressure
NH between DEG C4MgCl3·6H2O and NH4In the homogeneous mixture of Cl, the water vapour for generating pyrolysis is all taken away, thus
To anhydrous NH4MgCl3And NH4The mixture of Cl；
Third step, by NH4MgCl3And NH4The homogeneous mixture of Cl thermally decomposes under vacuum conditions and NH is distilled off4Cl is obtained
Anhydrous MgCl2。
2. the preparation method of anhydrous magnesium chloride with high purity according to claim 1, it is characterised in that in third step, anhydrous
NH4MgCl3And NH4The mixture of Cl moves into a tool, and there are two in the vacuum distilling apparatus of warm area, control high-temperature region at 400~700 DEG C
Between, low-temperature space is at 150 DEG C hereinafter, making NH4MgCl3The NH that thermal decomposition generates in high-temperature region3With HCl steam in low-temperature space chemical combination,
NH is formed again4Cl crystal, to make NH4Cl is all recycled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710601232.6A CN107162027B (en) | 2017-07-21 | 2017-07-21 | A kind of preparation method of anhydrous magnesium chloride with high purity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710601232.6A CN107162027B (en) | 2017-07-21 | 2017-07-21 | A kind of preparation method of anhydrous magnesium chloride with high purity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107162027A CN107162027A (en) | 2017-09-15 |
| CN107162027B true CN107162027B (en) | 2019-07-12 |
Family
ID=59818102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710601232.6A Active CN107162027B (en) | 2017-07-21 | 2017-07-21 | A kind of preparation method of anhydrous magnesium chloride with high purity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107162027B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1689973A (en) * | 2004-04-29 | 2005-11-02 | 中南大学 | Preparation method of high-purity anhydrous magnesium chloride |
| CN102491384A (en) * | 2011-12-01 | 2012-06-13 | 中国科学院过程工程研究所 | Method for preparing anhydrous magnesium chloride by utilizing magnesium chloride hexahydrate |
| CN102491382A (en) * | 2011-12-01 | 2012-06-13 | 中国科学院过程工程研究所 | Method for preparing anhydrous magnesium chloride by utilizing ammonium camallite |
| CN104495885A (en) * | 2015-01-05 | 2015-04-08 | 格尔木同兴盐化有限公司 | Method for preparing high-purity magnesium chloride from magnesium chloride hexahydrate |
-
2017
- 2017-07-21 CN CN201710601232.6A patent/CN107162027B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1689973A (en) * | 2004-04-29 | 2005-11-02 | 中南大学 | Preparation method of high-purity anhydrous magnesium chloride |
| CN102491384A (en) * | 2011-12-01 | 2012-06-13 | 中国科学院过程工程研究所 | Method for preparing anhydrous magnesium chloride by utilizing magnesium chloride hexahydrate |
| CN102491382A (en) * | 2011-12-01 | 2012-06-13 | 中国科学院过程工程研究所 | Method for preparing anhydrous magnesium chloride by utilizing ammonium camallite |
| CN104495885A (en) * | 2015-01-05 | 2015-04-08 | 格尔木同兴盐化有限公司 | Method for preparing high-purity magnesium chloride from magnesium chloride hexahydrate |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107162027A (en) | 2017-09-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104843712B (en) | A kind of method of the purification co-producing white carbon black of industrial fluosilicic acid | |
| CN105731482A (en) | Method for preparing potassium fluoborate from fluorine-containing wastewater | |
| CN110015671A (en) | A kind of preparation method of high purity magnesium oxide | |
| CN103641748B (en) | A kind of recycle by-product hydrochloric acid prepares the method for methylsulphonic acid | |
| CN104495889A (en) | Method for processing potassium-containing rock through industrial microwave | |
| CN106565246B (en) | A method of preparing aluminium nitride/yttrium nitride composite powder | |
| CN107162027B (en) | A kind of preparation method of anhydrous magnesium chloride with high purity | |
| CN104418370A (en) | Method and device for preparing anhydrous magnesium chloride | |
| CN105692575B (en) | A kind of Application way of rock phosphate in powder | |
| CN103011114A (en) | Method of producing monopotassium phosphate | |
| CN107473928A (en) | A kind of fluorobenzene preparation method | |
| CN106809827A (en) | The magnanimity preparation method of high connductivity iron chloride doped graphene nanometer sheet powder body material | |
| CN104556156B (en) | A kind of preparation method of anhydrous magnesium chloride | |
| CN104418378B (en) | XNH4br LaBr3yH2o, its preparation method and the preparation method of anhydrous lanthanum bromide | |
| CN101077786B (en) | Method for preparing aluminum fluoride | |
| CN102020293B (en) | Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production | |
| CN104495885B (en) | A kind of method utilizing magnesium halogen crystalline substance high purity magnesium chloride | |
| US3962408A (en) | Dehydration of magnesium chloride | |
| CN111036259A (en) | Preparation method of fluorine-doped carbon nitride nanosheet | |
| CN106745287A (en) | A kind of preparation method of high-pure anhydrous manganese chloride | |
| CN101805000B (en) | Production method of lithium terachloroaluminate | |
| CN102897769B (en) | Production technology of silicon tetrafluoride | |
| CN113044862A (en) | Method for dehydrating different ammonium carnallite materials by utilizing synergistic coupling effect of different ammonium carnallite materials | |
| CN106008397A (en) | Preparation method of pyrophosphate piperazine | |
| CN105732154A (en) | Method for preparing potassium fertilizer from potassium feldspar |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |